• Keep this leaflet. You may need to read it again.
• If you have any further questions, ask your doctor or pharmacist.
• If you get any side effects, talk to your doctor, pharmacist or nurse. This includes any possible side effects not listed in this leaflet. See section 4.

1. What Herzuma is and what it is used for
2. What you need to know before you are given Herzuma
3. How Herzuma is given
4. Possible side effects
5. How to store Herzuma
6. Contents of the pack and other information

• you are allergic to trastuzumab, to murine (mouse) proteins or any of the other ingredients of this medicine (listed in section 6).
• you have severe breathing problems at rest due to your cancer or if you need oxygen treatment.

Your doctor will closely supervise your therapy.

Treatment with Herzuma alone or with a taxane may affect the heart, especially if you have ever used an anthracycline (taxanes and anthracyclines are two other kinds of medicine used to treat cancer). The effects may be moderate to severe and could cause death. Therefore, your heart function will be checked before, during (every three months) and after (up to two to five years) treatment with Herzuma. If you develop any signs of heart failure (inadequate pumping of blood by the heart), your heart function may be checked more frequently (every six to eight weeks), you may receive treatment for heart failure or you may have to stop Herzuma treatment.

Talk to your doctor, pharmacist or nurse before you are given Herzuma if:

• you have had heart failure, coronary artery disease, heart valve disease (heart murmurs), high blood pressure, taken any high blood pressure medicine or are currently taking any high blood pressure medicine.
• you have ever had or are currently using a medicine called doxorubicin or epirubicin (medicines used to treat cancer). These medicines (or any other anthracyclines) can damage heart muscle and increase the risk of heart problems with trastuzumab.
• you suffer from breathlessness, especially if you are currently using a taxane. Trastuzumab can cause breathing difficulties, especially when it is first given. This could be more serious if you are already breathless. Very rarely, patients with severe breathing difficulties before treatment have died when they were given trastuzumab.
• you have ever had any other treatment for cancer.

If you receive Herzuma with any other medicine to treat cancer, such as paclitaxel, docetaxel, an aromatase inhibitor, capecitabine, 5-fluorouracil, or cisplatin you should also read the patient information leaflets for these products.

Herzuma is not recommended for anyone under the age of 18 years.

Tell your doctor, pharmacist or nurse if you are taking, have recently taken or may take any other medicines.

It may take up to 7 months for Herzuma to be removed from the body. Therefore you should tell your doctor, pharmacist or nurse that you have had Herzuma if you start any new medicine in the 7 months after stopping treatment.

• If you are pregnant, think you may be pregnant or are planning to have a baby, ask your doctor, pharmacist or nurse for advice before taking this medicine.
• You should use effective contraception during treatment with Herzuma and for at least 7 months after treatment has ended.
• Your doctor will advise you of the risks and benefits of taking Herzuma during pregnancy. In rare cases, a reduction in the amount of (amniotic) fluid that surrounds the developing baby within the womb has been observed in pregnant women receiving Herzuma. This condition may be harmful to your baby in the womb and has been associated with the lungs not developing fully resulting in foetal death.

Do not breast-feed your baby during Herzuma therapy and for 7 months after the last dose of Herzuma as Herzuma may pass to your baby through your breast milk.

Ask your doctor or pharmacist for advice before taking any medicine.

Herzuma may affect your ability to drive a car or operate machines. If during treatment you experience symptoms, such as dizziness, sleepiness, chills or fever, you should not drive or use machines until these symptoms disappear.

Do not stop using this medicine without talking to your doctor first. All doses should be taken at the right time every week or every three weeks (depending on your dosing schedule). This helps your medicine work as well as it can.

It may take up to 7 months for Herzuma to be removed from your body. Therefore your doctor may decide to continue to check your heart functions, even after you finish treatment.

Other side effects can occur at any time during treatment with Herzuma, not just related to an infusion.

Tell a doctor or nurse straight away, if you notice any of the following side effects:

• Heart problems can sometimes occur during treatment and occasionally after treatment has stopped and can be serious. They include weakening of the heart muscle possibly leading to heart failure, inflammation of the lining around the heart and heart rhythm disturbances. This can lead to symptoms such as breathlessness (including breathlessness at night), cough, fluid retention (swelling) in the legs or arms, palpitations (heart fluttering or irregular heart beat) (see section 2. Heart checks).
  Your doctor will monitor your heart regularly during and after treatment but you should tell your doctor immediately if you notice any of the above symptoms.
• Tumour lysis syndrome (a group of metabolic complications occurring after cancer treatment characterized by high blood levels of potassium and phosphate, and low blood levels of calcium). Symptoms may include kidney problems (weakness, shortness of breath, fatigue and confusion), heart problems (fluttering of the heart or a faster or slower heartbeat), seizures, vomiting or diarrhoea and tingling in the mouth, hands or feet.

If you experience any of the above symptoms when your treatment with Herzuma has finished, you should see your doctor and tell them that you have previously been treated with Herzuma.

Very common side effects (may affect more than 1 in 10 people):

• infections
• diarrhoea
• constipation
• heartburn (dyspepsia)
• fatigue
• skin rashes
• chest pain
• abdominal pain
• joint pain
• low counts of red blood cells and white blood cells (which help fight infection) sometimes with fever
• muscle pain
• conjunctivitis
• watery eyes
• nose bleeds
• runny nose
• hair loss
• tremor
• hot flush
• dizziness
• nail disorders
• weight loss
• loss of appetite
• inability to sleep (insomnia)
• altered taste
• low platelet count
• bruising
• numbness or tingling of the fingers and toes, which occasionally may extend to the rest of the limb
• redness, swelling or sores in your mouth and/or throat
• pain, swelling, redness or tingling of hands and/or feet
• breathlessness
• headache
• cough
• vomiting
• nausea

Common side effects (may affect up to 1 in 10 people):

• allergic reactions
• throat infections
• bladder and skin infections
• inflammation of the breast
• inflammation of the liver
• kidney disorders
• increased muscle tone or tension (hypertonia)
• pain in the arms and/or legs
• itchy rash
• sleepiness (somnolence)
• haemorrhoids
• itchiness
• dry mouth and skin
• dry eyes
• sweating
• feeling weak and unwell
• anxiety
• depression
• asthma
• infection of lungs
• lung disorders
• back pain
• neck pain
• bone pain
• acne
• leg cramps

Uncommon side effects (may affect up to 1 in 100 people):

• deafness
• bumpy rash
• wheezing
• inflammation or scarring of the lungs

Rare side effects (may affect up to 1 in 1000 people):

• jaundice
• anaphylactic reactions

Other side effects that have been reported with Herzuma use (frequency cannot be estimated from the available data):

• abnormal or impaired blood clotting
• high potassium levels
• swelling or bleeding at the back of the eyes
• shock
• abnormal heart rhythm
• respiratory distress
• respiratory failure
• acute accumulation of fluid in the lungs
• acute narrowing of the airways
• abnormally low oxygen levels in the blood
• difficulty in breathing when lying flat
• liver damage
• swelling of the face, lips and throat
• kidney failure
• abnormally low levels of fluid around baby in womb
• failure of the lungs of the baby to develop in the womb
• abnormal development of the kidneys of the baby in the womb

Some of the side effects you experience may be due to your underlying cancer. If you receive Herzuma in combination with chemotherapy, some of them may also be due to the chemotherapy.

If you get any side effects, talk to your doctor, pharmacist or nurse.

If you get any side effects, talk to your doctor, pharmacist or nurse. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via Yellow Card Scheme Website: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store. By reporting side effects you can help provide more information on the safety of this medicine.

• The active substance is trastuzumab. Each vial contains 150 mg trastuzumab that has to be dissolved in 7.2 mL of water for injection. The resulting solution contains approximately 21 mg/mL trastuzumab.
• The other ingredients are L-histidine hydrochloride, L-histidine, α,α-trehalose dihydrate, polysorbate 20.

Herzuma is a powder for concentrate for solution for intravenous infusion, which is supplied in a glass vial with a rubber stopper containing 150 mg of trastuzumab. The powder is a white to pale yellow pellet. Each carton contains 1 vial of powder.